The present invention relates to surgical methods and devices useful for removal of blood vessels. In particular, the invention relates to surgical methods and devices useful for removal of veins, including varicose veins, from human or animal subjects.
Blood vessel removal, and in particular vein removal, is a commonly-used procedure for treatment of conditions such as phlebotomy or saphenectomy. Blood vessel removal procedures generally include stripping out, i.e. removing, a diseased vein, and re-establishment of blood circulation via parallel paths. An entire blood vessel or a segment thereof may be removed.
Common surgical devices useful for removing blood vessels, known as xe2x80x9cstripping devices,xe2x80x9d or xe2x80x9cstrippers,xe2x80x9d include a rod, generally a semi-rigid rod, for insertion into the vein that is to be removed. Such devices are rigid or semi-rigid to facilitate catheterization (insertion into) and exeresis (removal) of blood vessels. In common procedures using rigid or semi-rigid rods or similar devices, the rod is inserted into and through the lumen of the vein to be removed. An end of the vein is ligated to the inserted end of the rod. The vein is removed by pulling on the opposite end of the rod to draw the ligated end of the vein or vein segment back toward the rod. The vein is a flexible tube, and pushing against one end of the flexible tube (or, more accurately, pulling backward toward the tube from the ligated end) causes the vein to fold and crumple accordion-wise into a lump of crumpled vein tissue at the end of the rod adjacent to the ligated end. Pulling the rod with this lump at the end, through the patient""s tissue for extraction of the vein, may result in injury to adjacent tissue, bleeding, and/or telangiectatic angioma of the skin along the extraction path.
FR-A-2 727 617 describes a vein-removing device for extracting a vein by invagination. The device comprises an elongated rod or wire with an anchoring part formed by a looped-back end of the rod or wire at a distal end, which provides a large diameter structure at the end of the small diameter rod or wire. The rod is inserted in a vein. A ligature is passed around the outside of the vein (and the rod therein) on the proximal side of the large diameter end structure, and cinched to a diameter less than that of the end structure, to fix the vein to the end of the rod. The rod is pulled in the direction of its proximal end, pulling the vein along from the attachment at the distal end of the rod. The rod and the vein can be maneuvered in one direction or in the other direction. In an optional embodiment the rod resides in a plastic sheath that is carried along with the rod. The device still requires a rigid rod even though it could slide in the sheath but for the enlarged structure at the end of the rod, which is wider than the sheath.
AU-B-60597 describes a stripper formed by an oriented monofilament cable whose ends form guides that facilitate snaking of the cable through a vein. A bullet-shaped traveler of a diameter greater than that of the guides is mounted on one of the ends. An end of the vein is attached to the end of the monofilament cable, using a cinched ligature as above. The monofilament cable may not be sufficiently flexible to snake through sinuous paths of some varicose veins, and like other rods that are only somewhat flexible, tends to stretch the vein out straight upon insertion and to crumple the vein along the cable when pulled back.
A need remains for new and/or improved surgical devices for use in partially or completely stripping blood vessels. The present invention is directed to these and other important ends.
One aspect of the present invention is a device for stripping blood vessels. The device includes a semi-rigid rod having two ends, and a flexible thread secured to one end of the rod for inserting the thread into and through the vein using the rod. The rod can then be removed. The end of the vein is attached at an intermediate point along the thread. The thread is used bidirectionally for pulling the vein generally in one direction for stripping but also permitting reversal of direction to back up and try again in passing sinuous passages and other structures that may impede progress.
Preferably, the length of the thread is at least about twice the length of the rod, so that the rod can be used to insert the thread sufficiently to bring a midpoint of the thread up to an end of the vein. Thus half of the thread extends through the vein to the insertion point and the other half protrudes beyond the vein from the end opposite from the insertion point. This opposite end of the vain is attached to the thread at the midpoint of the thread. Both ends of the thread remain accessible throughout the procedure and permit the midpoint and attached end to be pulled back and forth.
By pulling the thread in one direction, the end of the vein is pulled back by the thread into the lumen of the vein, progressively turning the vein inside out and following along the path of the vein as it is stripped out without forming a lump on the thread. At any snags or obstructions that are encountered, the thread can be pulled from the other end for a short distance (i.e., in the opposite direction) and then reversed again in an effort to pass by the snag or obstruction and continue stripping the vein.
Preferably the vein is stripped entirely in this manner, but it is possible that the vein may crumple and collapse on the thread in the area leading up to the midpoint and the ligated end. Therefore, in some embodiments of the invention, the device further comprises a stop element that can be affixed on the thread. Preferably the stop element is located at about the middle of the thread. The stop element has a larger diameter than the vein and positively crumples the vein on the thread leading to the stop element. The stop element is used if the surgeon gives up the attempt to strip the vein in the preferred way, namely by turning it inside out while pulling the ligated end back into the lumen of the vein.
In preferred embodiments, the thread is made of a polymeric material. The thread can be thin and flexible and of sufficient strength to be pulled manually from either end during the stripping procedure.
Another aspect of the present invention is a method for removing a blood vessel from a part of a body of a patient. The method includes making a first incision and a second incision in the portion of the body from which the blood vessel is to be removed, namely to gain access to a first end of the blood vessel proximate to the first incision and a second end proximate to the second incision. The next step is incising and extracting the first end of the blood vessel; and incising and extracting the second end of the blood vessel. A semi-rigid rod is inserted into the blood vessel from one end (the first end of the blood vessel) and at the insertion end of the rod carries along a flexible thread. The rod and the thread it carries are moved through the blood vessel until substantially all of the rod is inserted and the insertion end carrying the thread emerges from the second end of the blood vessel. The thread is at least twice the length of the blood vessel, and protrudes at both ends of the blood vessel. A midpoint of the thread is located at or near one end of the blood vessel (e.g., the first end), where a length of thread at least as long as the blood vessel extends out of the blood vessel. At the opposite end of the blood vessel (a second end), the thread protrudes at least slightly. The thread can be grasped manually or with a tool at both ends of the blood vessel.
The first end of the blood vessel is affixed to the thread at the midpoint. The first end can be sutured to the thread. The blood vessel is stripped or removed by pulling the thread in a direction from the first end of the blood vessel toward the second end of the blood vessel. The rod, which is needed only to insert the thread initially through the blood vessel so as to be accessible at both ends, can be removed. Both ends of the thread remain accessible until the vein is completely stripped out. At any point in the procedure, a stop can be affixed on the thread near the end of the blood vessel on the first side. The stop has a greater diameter than the blood vessel or the diameter of the blood vessel is cinched ahead of the stop to prevent passage of the stop therethrough, or the blood vessel is ligated to the thread or the stop. When using the stop, the blood vessel may become crumpled along the thread. The stop can be used if necessary to strip the blood vessel, namely when pulling the vein backwards from the midpoint of the thread encounters problems such as an obstruction preventing further progress.
These and other aspects of the invention will be apparent to those skilled in the art in view of the present disclosure and the appended claims.